Gizmodo has been having a play around with iPhone OS 4.0 beta 4 and has revealed a few more changes.

Firstly, the homescreen is different - it uses the folders functionality we all knew was coming to group the clock, calculator, compass and voice memo native apps into a "utilities" folder. Presumably you'll be able to move these out of this folder and back onto the front screen if that's what you'd prefer.

Sticking with the homescreen, Apple has added some more wallpaper options to the 19 that are currently available, although don't worry if you like the current selection as they all still seem to be present.

A major change, especially in the US, could be the one found within the network settings, where there is now an option to turn tethering on. This option is already available to UK iPhone users, but finally AT&T are giving US users this option. Like the UK though, this will undoubtedly come at a cost.

A minor change is that you can now look at your photo roll in landscape which, bizarrely, you couldn't do before.

Gizmodo is also saying that OS 4.0 handles calls better, with no pause at the beginning of calls and that apps, including Google Maps, seem a bit zippier.

Add these features to the ones we already know about like the multitasking shelf, the orientation lock and the new iTunes controls and we're looking at a pretty major upgrade. We're excited anyway. How's about you?